For many years there has been made efforts to develop loudspeaker enclosures or cabinets which were in acoustical sense totally dead, also in replaying pieces of music at very high sound levels. After all, the purpose is to achieve a neutral reproduction of the electrical signals conducted to the loudspeaker system without colouring the sound picture due to cabinet resonances or other interfering noise sources. This problem has hitherto been solved in many different ways.
Thus, it is known to manufacture enclosures or cabinets of heavy or thick blockboards and further to brace them by means of strong bars. This is a fairly good but costly method, because wood of this quality is expensive. It is also a known method to manufacture the enclosure or cabinet as a double-walled box of e.g. chip board and then fill out the space between the outer and inner box with sand so that the cabinet obtains a considerable weight. In acoustical sense this is an excellent solution because the cabinet by this measure can be kept absolutely in rest. For such goods, however, which have to be transported over long distances, maybe in more than one stage, and which, moreover, have to be stored in large numbers of specimens, this weight is of a prohibitive nature. The same applies to those constructions of concrete or marble which have been disclosed recently in the litterature.